將訊息傳送到 sendmail 的格式是什麼？

Question

我使用以下命令動態建立訊息並發送它們：

echo "Subject:Hello \n\n I would like to buy a hamburger\n" | sendmail [email protected]

似乎當您從文件發送訊息時，可以透過執行以下操作：

sendmail [email protected] mail.txt 

然後 sendmail 將每一行視為標頭，並對其進行解析。但按照我上面發送的方式，所有內容最終都在主題行中。

如果想將帶有標頭的訊息回顯到 sendmail 中，那麼格式是什麼？如何做到這一點？

Answer 1

您的語句實際上應該輸出換行符，而不是後面跟著的echo序列。您可以透過提供以下選項來做到這一點：\n-e

echo -e "Subject:Hello \n\n I would like to buy a hamburger\n" | sendmail [email protected]

要了解有何區別，請查看以下兩個命令的輸出：

echo "Subject:Hello \n\n I would like to buy a hamburger\n"
echo -e "Subject:Hello \n\n I would like to buy a hamburger\n"

Answer 2

shell 腳本中的「此處文件」（您編寫訊息標題和正文）

#!/bin/sh
[email protected]
/usr/sbin/sendmail -i $TO <<MAIL_END
Subject: Hello
To: $TO

I would like to buy a hamburger
MAIL_END

來自外部文件的訊息正文

#!/bin/sh
[email protected]
BODY_FILE=mail.txt
(cat - $BODY_FILE)<<HEADERS_END | /usr/sbin/sendmail -i $TO
Subject: Hello
To: $TO

HEADERS_END